These GM combination-proportioning valves are based on the popular AC DELCO 172-1353(disc-drum) and 172-1361(disc-disc) valves. When upgrading your vehicle from drum to disc, these small items are a must.

All valves contain a low pressure shut off valve and warning light switch to ensure driver and vehicle safety should your brake system lose hydraulic line pressure. Aftermarket imported master cylinders with built in adjustable proportioning valves DO NOT feature this and could put you and your vehicle at risk.